Question

Bombarding plutonium-239 with an alpha particle creates an isotope of curium. Balance the equation.


239
94
Pu +
4
2
He →
a
b
Cm +
c
d
n

Identify the values for the unknown letters.

a is

b is

c is

d is

Answer 1

Write conservation of mass and charge:

Mass: 239 + 4 = a + c → 243 = a + c
Charge: 94 + 2 = b + d → 96 = b + d

For a neutron, mass = 1 and charge = 0, so c = 1 and d = 0. Then a = 243 − 1 = 242 and b = 96.

a = 242
b = 96
c = 1
d = 0